1. Field of the Invention
The invention relates to a device for clamping off organic tissue, particularly blood vessels. It can particularly be used in minimally invasive surgery.
2. The Prior Art
A device for clamping off organic tissue is described in European Patent No. EP 0 178 469. This device has a distal and a proximal clamping bar, which extend perpendicularly from an application crosspiece. The proximal clamping bar can be displaced in the direction of the distal clamping bar, and the tissue can be clamped off between them. Finally, the tissue clamp formed in this way can be removed from the application crosspiece by way of a tappet that surrounds the application crosspiece and is displaceable longitudinally to it, for which purpose a planned breaking point is assigned to the application crosspiece, and a locking and unlocking device is assigned to the base of the distal clamping bar. The disadvantages of this device can be seen as being, in particular, its complicated structure and its difficult handling.
In particular, it is difficult to equip the application crosspiece with the clamping bar. This presupposes that the proximal clamping bar is always disposed in front of the distal one. Furthermore, secure fixation of the clamping bars relative to one another, in their end position, is nearly impossible.
U.S. Pat. No. 4,651,737 describes a releasable device for clamping off organic tissue, in which the distal clamping bar can be connected with the application crosspiece by a journal-like connection. The proximal clamping bar, which can be displaced in the longitudinal direction with an internal pushing device, is disposed on the crosspiece. With this device, the clamping bars are pushed over one another, seizing the organic tissue, to such an extent that the tissue is finally fixed in place by a shearing/clamping effect, and the tissue clamp can subsequently be released from the application crosspiece, under a pressure that is not slight.
However, this device has the problem that the clamping bars, with their clamping crosspieces, which are partly meshed with gears, have a predetermined and unchangeable distance relative to one another during closing. As a result, step-free clamping of organic tissue, depending on the compression pressure, is not possible with this device. Clamping takes place without any consideration of the type of tissue and the existing conditions, such as the thickness of a blood vessel, for example. Because of the shearing/clamping effect by means of which the tissue is fixed in place, there is the risk of injury to the tissue, all the way to unintentionally cutting through tissue.